scholarly journals Wettability and Color Change of Thermally Treated Poplar OSB after Accelerated Weathering Test

2018 ◽  
Author(s):  
Francesco Negro ◽  
Paola Cetera ◽  
Corrado Cremonini ◽  
Luigi Todaro ◽  
Roberto Zanuttini
Keyword(s):  
Thermal Treatment ◽  
Color Change ◽  
Oriented Strand Board ◽  
Accelerated Weathering ◽  
Poplar Wood ◽  
Industrial Coating ◽  
Accelerated Weathering Test ◽  
Coniferous Wood ◽  
Main Components ◽  
Thermally Treated

Oriented strand board (OSB) panels are widely marketed for several applications, from building to packaging. The manufacturing of poplar OSB started recently in Northern Italy representing a relevant innovation in the sector since this product is usually made of coniferous wood. The thermal treatment is widely used for reducing the hygroscopicity of wood-based products, nonetheless it influences the mechanical behavior and degrades the main components of wood, which can affect their finishing. Therefore, it is important to know the properties of the treated surfaces. To this purpose, in this study a lot of OSB panels, made of poplar wood, 15 mm thick and with a density of 590 kg/m3, were thermally treated under vacuum conditions at 190 °C for 2 h and then subjected to accelerated weathering. The changes in color and in wettability due to treatment and accelerated weathering were studied. The thermal treatment determined a significant darkening of the color; the accelerated weathering darkened the untreated surfaces and, on the opposite, lightened the thermo-treated surfaces. The wettability decreased after thermal treatment and increased after weathering, more evidently in treated panels. Overall, this study improves the knowledge about the behavior of the surface of thermo-treated poplar OSB, which is relevant for the industrial coating of this product.

scholarly journals Effects of UV, humidity, and high temperature exposure on linen fibers

2020 ◽  
Author(s):  
Irina Sandulache ◽  
Mihaela-Cristina Lite ◽  
Lucia-Oana Secareanu ◽  
Elena-Cornelia Mitran ◽  
Ovidiu Iordache ◽  
...  
Keyword(s):  
High Temperature ◽  
Color Change ◽  
Chemical Elements ◽  
Environmental Parameters ◽  
Accelerated Weathering ◽  
Textile Materials ◽  
Starting Point ◽  
Accelerated Weathering Test ◽  
Temperature Exposure ◽  
Natural Decay

Generally, the most common damaging factors for linen textile materials are the environmental conditions, their handling, and natural decay. Such environmental factors are ultraviolet (UV) radiation, humidity, and high temperature. Therefore, to investigate the effects these factors may cause, an accelerated weathering test was conducted on linen fabrics, using alternating cycles of UV exposure and humidity, along with relatively high temperatures. The effects of this test were investigated using non-destructive and micro-destructive analysis techniques. Scanning Electron Microscopy (SEM) was used to observe any modifications appearing at the surface of the fibers. Energy Dispersive X-Ray Analysis (EDS) was employed in conjunction with SEM for obtaining the spectrum of the chemical elements that were present at the surface of the linen samples. The modifications of functional groups occurring due to the weathering of linen were assessed by Fourier-Transform Infrared Spectroscopy (FT-IR). The color change of the samples was measured with a spectrophotometer. All the acquired information can be used as a starting point for the development of customized environmental parameters for keeping patrimony linen fabrics in museums in optimum conditions, thus preventing further damage. Additionally, the artificially weathered fabrics will be further employed in conservation experiments as substitute for old linen fabrics.

scholarly journals Comparison of the Physico-Mechanical and Weathering Properties of Wood–Plastic Composites Made of Wood Fibers from Discarded Parts of Pomelo Trees and Polypropylene

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2681
Author(s):  
Ke-Chang Hung ◽  
Wen-Chao Chang ◽  
Jin-Wei Xu ◽  
Tung-Lin Wu ◽  
Jyh-Horng Wu
Keyword(s):  
Color Change ◽  
Flexural Modulus ◽  
Modulus Of Rupture ◽  
National Standard ◽  
Accelerated Weathering ◽  
Wood Fibers ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Initial Stage ◽  
Accelerated Weathering Test

The purpose of this study is to compare the characteristics of wood–plastic composites (WPCs) made of polypropylene (PP) and wood fibers (WFs) from discarded stems, branches, and roots of pomelo trees. The results show that the WPCs made of 30–60 mesh WFs from stems have better physical, flexural, and tensile properties than other WPCs. However, the flexural strengths of all WPCs are not only comparable to those of commercial wood–PP composites but also meet the strength requirements of the Chinese National Standard for exterior WPCs. In addition, the color change of WPCs that contained branch WFs was lower than that of WPCs that contained stem or root WFs during the initial stage of the accelerated weathering test, but the surface color parameters of all WPCs were very similar after 500 h of xenon arc accelerated weathering. Scanning electron microscope (SEM) micrographs showed many cracks on the surfaces of WPCs after accelerated weathering for 500 h, but their flexural modulus of rupture (MOR) and modulus of elasticity (MOE) values did not differ significantly during weathering. Thus, all the discarded parts of pomelo trees can be used to manufacture WPCs, and there were no significant differences in their weathering properties during 500 h of xenon arc accelerated weathering.

scholarly journals The effect of using alum mordant in wild cherry bark dyestuff for the production of UV resistant colored paper

2019 ◽  
Vol 70 (4) ◽  
pp. 383-390
Author(s):  
Ayhan Gençer ◽  
Ahmet Can ◽  
Aysun Mustak ◽  
Ülkü Burcu Gitti
Keyword(s):  
Color Change ◽  
Tree Bark ◽  
Thermomechanical Pulp ◽  
Accelerated Weathering ◽  
Wild Cherry ◽  
Cherry Tree ◽  
Accelerated Weathering Test ◽  
Colored Paper ◽  
Environmentally Friendly Method

Depending on the use of wood in the forest industry, wood bark is mostly peeled and used as fuel. The ash and smoke left from the burned bark causes environmental pollution. The most environmentally friendly method for waste disposal is to convert waste into a valuable commodity. In this study, cherry tree bark was used as a dyestuff in paper production. Wild cherry (Cerasus avium L.) bark was boiled with water and KOH. The purpose of using KOH is to increase the solubility of the bark compounds. The chemi-thermomechanical pulp (CTMP) was dyed using the dyestuff. The alum mordant is used to fi x the dyestuff. Paper can be exposed to external influences (mechanical, physical and biological) depending on the place of use. One of these effects is sunshine. When paper is exposed to direct or indirect sunlight, paper changes its color. Depending on the place of use, it is expected that the color of the paper will not be affected by the sunlight or that it will provide long-term strength after the application. Accelerated weathering test was chosen to measure the UV resistance of the dyestuff. The results have shown that the mordant has a significant effect on the fixation of dyestuff. After a total of 150 hours of weathering test, the color change was observed to be the lowest in the paper samples to which alum mordant was added to the dyestuff.

Reddening by UV Irradiation after Smoke-Heating in Sugi (Cryptomeria japonica D. Don) Black Heartwood

Holzforschung ◽  
2001 ◽  
Vol 55 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Saori Maruyama ◽  
Futoshi Ishiguri ◽  
Minoru Andoh ◽  
Zensaku Abe ◽  
Shinso Yokota ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Uv Irradiation ◽  
Cryptomeria Japonica ◽  
Color Change ◽  
Ph Value ◽  
Uv Light ◽  
Japanese Cedar ◽  
Color Changes ◽  
Black Heartwood ◽  
Thermally Treated

Summary Sugi (Japanese cedar, Cryptomeria japonica D. Don) green logs with black heartwood were smoked, heated, and smoke-heated separately to improve the heartwood color. After each treatment, changes in heartwood color, pH, and extract amounts were examined. In addition, changes in heartwood color caused by UV irradiation were observed. Heating and smoke-heating of logs prevented the heartwood from discoloring to black, and the resulting color of thermally-treated heartwoods was yellow-white, whereas smoking alone allowed discoloration to black. The pH value decreased from the original 7.6 to 6.8 by smoking and to 6.5 by thermal treatment. The results obtained here suggest that a pH drop in heartwood by thermal treatment is involved in color changes of black heartwood. When thermally-treated black heartwood was exposed to UV light, redness and yellowness increased and brightness decreased. The resulting color tone was reddish brown. The color of non-thermally-treated woods, however, showed little change. Furthermore, acetone, ethanol, and methanol extracts of thermally-treated black heartwood showed an increase in redness by UV irradiation, but the residues showed little color change. The coloring substances relating to the reddening of heartwood could be extracted with these solvents, particularly with methanol. Reddening in black heartwood by a combination of smoke-heating and UV irradiation is considered to be due to a decrease in brightness and an increase in both redness and yellowness.

scholarly journals A multilevel investigation supported by multivariate analysis for tomato product formulation

2021 ◽  
Author(s):  
Fatma Boukid ◽  
Elena Curti ◽  
Agoura Diantom ◽  
Eleonora Carini ◽  
Elena Vittadini
Keyword(s):  
Thermal Treatment ◽  
Color Change ◽  
Water Molecules ◽  
Thermal Treatments ◽  
Industrial Processing ◽  
H Nmr ◽  
Mobile Populations ◽  
Product Formulation ◽  
Tomato Product ◽  
The Impact

AbstractIndustrial processing of tomato includes its cutting and mincing, thermal treatments, and the addition of ingredients, which might induce changes in physicochemical properties of the final products. In this frame, the impact of texturing/thickening [xanthan gum (X) or potato fiber (F)] on the macroscopic, mesoscopic and molecular properties of tomato double concentrate (TDC) was investigated to determine if F can efficiently substitute X, in association with small solutes (sugar and salt) and thermal treatment (cold and hot). At a macroscopic level, multivariate statistics (MANOVA) underlined that color change (ΔE) was increased by X and F addition contrary to heating and the addition of salt and sugar. MANOVA revealed that texture was greatly enhanced through the use of F over X. 1H NMR molecular mobility changes were more controlled by texturing agents (F and X) than thermal treatment and small solutes. Particularly F increased the more rigid population indicating stronger interaction with water molecules resulting in shear-thinning flow. However, adding X contributed into the increase of the dynamic and mobile populations. Therefore, F can be a valid “clean label” substitute of X in modulating tomato products properties.

Study of the Bioactive Behavior of Thermally Treated Modified 58S Bioactive Glass

2008 ◽  
Vol 396-398 ◽  
pp. 131-134 ◽  
Author(s):  
Ourania Menti Goudouri ◽  
Xanthippi Chatzistavrou ◽  
Eleana Kontonasaki ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Bioactive Glass ◽  
Sol Gel ◽  
Bioactive Glasses ◽  
X Ray ◽  
Characteristic Temperatures ◽  
Calcium Silicates ◽  
Crystal Phases ◽  
Thermally Treated

Thermal treatment of bioactive glasses can affect their microstructure and thus their bioactivity. The aim of this study was the characterization of the thermally treated sol-gel-derived bioactive glass 58S at characteristic temperatures and the dependence of its bioactive behavior on the specific thermal treatment. The thermal behavior of the bioactive glass was studied by thermal analysis (TG/DTA). Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffractometry (XRD) were used for the characterization of the bioactive glass. The bioactive behavior in Simulated Body Fluid (SBF) was examined by Scanning Electron Microscopy (SEM-EDS) and FTIR. The major crystal phases after thermal treatment were Calcium Silicates, Wollastonite and Pseudowollastonite, while all thermally treated samples developed apatite after 48 hours in SBF. A slight enhancement of bioactivity was observed for the samples heated at the temperature range 910-970oC.

Moisture Transport in Wood-Based Structural Panels under Transient Hygroscopic Conditions

2020 ◽  
Vol 70 (3) ◽  
pp. 283-292
Author(s):  
Daniel Way ◽  
Frederick A. Kamke ◽  
Arijit Sinha
Keyword(s):  
Moisture Transport ◽  
Transport Model ◽  
Oriented Strand Board ◽  
Primary Objective ◽  
Accelerated Weathering ◽  
Wood Composite ◽  
Transport Parameters ◽  
Moisture Profile ◽  
Cyclic Changes ◽  
Wood Based Composite

Abstract Development of moisture gradients within wood and wood-based composites can result in irreversible moisture-induced damage. Accelerated weathering (AW), generally employing harsh environmental conditions, is a common tool for assessing moisture durability of wood composite products. Use of milder AW conditions, such as cyclic changes in relative humidity (RH), may be of interest to the wood-based composites industry in assessing moisture durability under more realistic conditions. The primary objective of this study was to determine whether moisture profile development in oriented strand board and plywood during cyclic RH changes could be reasonably predicted with a simple moisture transport model, which may be practical for wood-based composite industry members seeking to develop new AW protocols. The diffusion model based on Fick's second law with empirically determined moisture transport parameters fits the experimental data reasonably well for the purpose of screening RH parameters.

Sign in / Sign up

Export Citation Format

Share Document